Disc cartridge

ABSTRACT

A disc cartridge is provided. The disc cartridge in which is housed an optical disc includes a main cartridge body unit, rotatably housing an optical disc, and having an aperture for a head part for exposing a part of the optical disc to outside across the inner and outer rims of the optical disc, and a shutter unit mounted for movement to this main cartridge body unit for opening/closing the aperture for the head part. A recess into which is introduced a portion of a head part of the recording and/or reproducing apparatus is formed in continuation to the aperture for the head part in a surface of the main cartridge body unit on which slides a shutter unit in an area opposite to the area of movement of the shutter unit with the aperture for the head part in-between.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 10/528,112 filed on Mar. 16, 2005 now U.S. Pat. No. 7,555,763 WHICHWAS THE National Stage of International Application No.PCT/JP2004/010516 filed on Jul. 23, 2004 and which claims priority toJapanese Patent Application Nos. 2003-281389 and 2003-281392, filed inJapan on Jul. 28, 2003, and Japanese Patent Application Nos. 2004-140473and 2004-140498, filed in Japan on May 10, 2004, the disclosures ofwhich in entirety are incorporated by reference herein.

BACKGROUND

The present invention relates to a disc cartridge having a disc-shapedrecording medium, such as an optical disc held therein, and to arecording and/or reproducing apparatus, employing the disc cartridge asa recording medium.

Up to now, a disc cartridge, having a disc-shaped recording medium, suchas an optical disc, rotatably housed therein, which disc cartridge isloaded on a disc recording and/or reproducing apparatus, as thedisc-shaped recording medium is housed therein, has been in useextensively. This sort of the disc cartridge, comprising a disc-shapedrecording medium, housed in a main cartridge body unit, can be loaded onor unloaded from the disc recording and/or reproducing apparatus, withthe disc-shaped recording medium in a protected state.

As this sort of the disc cartridge, such a one comprising a disc-shapedrecording medium, housed for rotation in a rectangular-shaped maincartridge body unit, is in widespread use.

Meanwhile, in a disc cartridge, attempts are being made to reduce itssize in keeping with the size of the disc-shaped recording medium,housed therein, with a view to reducing the size of the disc recordingand/or reproducing apparatus, assuring facilitated handling of the disccartridge, and to reducing the cartridge material and reducing theproduction cost.

With the disc cartridge, demand is also raised for increasing therecording capacity, in addition to reducing its size. The demand forincreasing the recording capacity for the information signals may be metby increasing the recording density and by increasing the recording areaprovided on the disc-shaped recording medium.

Such a disc cartridge in which the cartridge size is reduced in keepingwith the disc-shaped recording medium housed therein is disclosed in theJapanese Laid-Open Patent Publication H-11-353845.

With the disc cartridge, disclosed in Patent Publication 1, the size ofthe disc cartridge itself is reduced by having a substantially arcuatelateral surface, acting as an inserting end into the recording and/orreproducing apparatus.

The disc cartridge, disclosed in the above Publication, includes arecording and/or reproducing aperture, opened/closed by a shutter memberprovided to a main cartridge body unit, having an optical disc housedtherein, and the optical disc is partially exposed to outside via thisrecording and/or reproducing aperture. The information signals arerecorded and/or reproduced for the optical disc as an optical pickup ofa recording and/or reproducing head part is exposed to outside the maincartridge body unit via this recording and/or reproducing aperture.

With the recording and/or reproducing apparatus, employing this disccartridge as a recording medium, the optical pickup is moved along theradius of the optical disc, at a position spaced apart from the disccartridge to scan the signal recording area of the optical disc with alight beam to record and/or reproduce the information signals. With therecording and/or reproducing apparatus, recording and/or reproducing theoptical disc in accordance with this system, the optical pickup is movedat a position spaced apart from the disc cartridge, and hence there areimitations to reducing the thickness of the apparatus by reducing itsheight.

Meanwhile, in disc cartridges, used up to now, inclusive of the disccartridge disclosed in the Japanese Laid-Open Patent PublicationH-11-353845, the recording and/or reproducing aperture for exposing thesignal recording area of the disc-shaped recording medium to outside isformed in a plane of the main cartridge body unit. In the case of thissort of the disc cartridge, the recording and/or reproducing head has tobe moved within the range of the recording and/or reproducing apertureformed in the plane of the main cartridge body unit, in order to scanthe signal recording area of the disc-shaped recording medium, with theresult that the signal recording area cannot be extended efficiently upto the outer rim of the disc-shaped recording medium.

When an optical disc, in which attempts have been made for increasingthe recording density, is used as a disc-shaped recording medium, anoptical disc, having an objective lens of a high numerical aperture(NA), is used as a recording and/or reproducing head, for furtherreducing the beam diameter of a light beam scanning the signal recordingarea of the optical disc. With the use of this sort of the opticalpickup, it is necessary for the optical pickup to be at a position closeto the optical disc and, to this end, it is necessary for at least aportion of the optical pickup to be introduced into the disc cartridge.If the portion of the optical pickup intrudes into the disc cartridge,there is placed limitation to the area of possible movement of theoptical pickup, such that the signal recording area cannot efficientlybe extended up to the outer rim of the disc-shaped recording medium.

That is, with the conventional disc cartridge, it is difficult toenlarge the signal recording area of the disc-shaped recording medium,arranged therein, so that it is difficult to increase the recordingcapacity if the disc-shaped recording medium is to be reduced in size atthe same time.

SUMMARY

The present invention relates to a disc cartridge, having a disc-shapedrecording medium, such as an optical disc held therein, and to arecording and/or reproducing apparatus, employing this disc cartridge asa recording medium.

The present invention provides in an embodiment a disc cartridge withwhich the recording and/or reproducing apparatus can be reduced inthickness.

The present invention provides in an embodiment a disc cartridge withwhich the recording and/or reproducing apparatus may be reduced inthickness at the same time as the disc cartridge is reduced in size.

The present invention provides in an embodiment a disc cartridge withwhich a disc housed therein may be protected reliably.

The present invention provides in an embodiment a disc cartridge withwhich a shutter member for opening/closing the recording and/orreproducing aperture formed in the main cartridge body unit may beimproved in strength to enable the reliable opening/closure of therecording and/or reproducing aperture.

The present invention provides in an embodiment a disc cartridge withwhich the recording capacity may be increased at the same time as thedisc housed therein is reduced in size.

A disc cartridge according to the present invention comprises a disc,and a main cartridge body unit having the disc rotatably housed thereinand including a recording and/or reproducing aperture for exposing aportion of the disc to outside across inner and outer rims of the disc,wherein an entrance part for a head unit provided to a recording and/orreproducing apparatus is formed in continuation to the recording and/orreproducing aperture, for entrance of at least a portion of the headpart.

The entrance part for the head unit is an opening continuing to therecording and/or reproducing aperture.

A lateral surface of the entrance part for the head unit is an inclinedsurface for inhibiting abutment against the head part.

The disc cartridge according to the present invention further comprisesa shutter unit for opening/closing the recording and/or reproducingaperture. The entrance part for the head unit is formed as a recess, incontinuation to the recording and/or reproducing aperture, in a surfaceon which slides the shutter unit.

A bent part for closing the space produced between the shutter memberand the entrance part for the head unit when the shutter unit has beenmoved to a position of closing the recording and/or reproducing apertureis formed on one side of the shutter member of the shutter unit closingthe recording and/or reproducing aperture.

A recessed shutter slide part is formed in an area of a surface of themain cartridge body unit, on which slides the shutter member. Theentrance part for the head unit is formed as a recess of a depth deeperthan the depth of the shutter slide part.

A recording and/or reproducing apparatus according to the presentinvention comprises a disc, a main cartridge body unit having the discrotatably housed therein and including a recording and/or reproducingaperture for exposing a portion of the disc to outside across inner andouter rims of the disc, a cartridge loading unit for loading a disccartridge, including a recess continuing to the recording and/orreproducing aperture, thereon, and recording and/or reproducing meansfor recording and/or reproducing the information for the disc housed inthe disc cartridge. When the recording and/or reproducing means isintroduced via the recording and/or reproducing aperture for recordingand/or reproducing the information for the disc, a portion of therecording and/or reproducing means is introduced into the recess.

The recording and/or reproducing means is composed of an objective lensand an optical block. When the objective lens is introduced via therecording and/or reproducing aperture for recording and/or reproducingthe information for the disc, the optical block is introduced into therecess.

A disc cartridge according to the present invention comprises a disc,and a main cartridge body unit having the disc rotatably housed thereinand including a recording and/or reproducing aperture for exposing aportion of the disc to outside across inner and outer rims of the disc.The portion of the recording and/or reproducing aperture along the outerrim of the main cartridge body unit is opened by being formed with acut-out extending from the loading surface on a recording and/orreproducing apparatus in a direction along the thickness of the disc.

The cut-out formed in the main cartridge body unit is formed so that,when the disc cartridge is introduced into and loaded in position on therecording and/or reproducing aperture for recording and/or reproduction,the cut-out is of a height at least equal to a height as from theloading surface to the recording and/or reproducing apparatus up to asetting surface for rotation driving means for the disc.

In the present disc cartridge, the inserting lateral side of the maincartridge body unit into the recording and/or reproducing apparatus is asubstantially semicircular arcuate section, having a centercorresponding to the center of the disc housed in the main cartridgebody unit, and a recording and/or reproducing aperture is formed facingto a lateral side of the main cartridge body unit other than theinserting lateral side arcuate in profile.

When the disc cartridge according to the present invention is loaded onthe recording and/or reproducing apparatus, part of the head part forrecording and/or reproducing apparatus may be located in an entranceaperture for the head part formed in continuation to the recordingand/or reproducing aperture, with the consequence that the recordingand/or reproducing apparatus may be reduced in size.

Since one lateral side of the entrance aperture for the head part isformed as an inclined surface section for preventing abutment againstthe head part, it is possible to prevent the head part from collidingagainst the rim of the entrance aperture, when the head part is beingintroduced into the entrance aperture, thus assuring stable movement ofthe head part such as to enable the disc to be scanned correctly by thehead part.

By providing the shutter unit, adapted for closing the recording and/orreproducing aperture, the spacing between the shutter member and therecess may be closed by the bent part formed on one side of the shuttermember, when the shutter unit has moved to a position of closing therecording and/or reproducing aperture, so that the recording and/orreproducing aperture may be hermetically closed to prevent dust and dirtfrom intruding via recording and/or reproducing aperture to assurereliable protection of the disc housed in the main cartridge body unit.

Since the entrance aperture for the head part, provided to the maincartridge body unit, is formed as a recess deeper in depth than theslide part along which slides the shutter unit, a larger proportion ofthe head part may intrude into the inside of the main cartridge bodyunit, with the consequence that the recording and/or reproducingapparatus may further be reduced in size.

With the recording and/or reproducing apparatus, according to thepresent invention, in which, when the recording and/or reproducing meansis introduced into the recording and/or reproducing aperture forrecording and/or reproducing the information for the disc, part of therecording and/or reproducing means is introduced into the recess formedin the disc cartridge, the apparatus itself may be reduced in size.

When the disc cartridge according to the present invention is loaded onthe recording and/or reproducing apparatus, the recording and/orreproducing head may be located via cut-out across the inner rim and theoutside of the main cartridge body unit, as a result of which the headpart may scan up to the outermost area of the disc to increase thesignal recording area as well as the recording capacity.

Additionally, when the disc cartridge according to the present inventionis loaded on the recording and/or reproducing apparatus, the head partprovided to the recording and/or reproducing apparatus may be introducedinto the inside of the main cartridge body unit, as the head part ispositioned as from the inner rim up to the outside of the main cartridgebody unit. The result is that the head part may be brought to theproximity of the head part, such that, when an optical disc is used as adies, an optical pickup having a high NA (numerical aperture) objectivelens may be used as a head part, thus achieving a high recording densityof the optical disc.

With the disc cartridge according to the present invention, therecording capacity of the disc may be increased, as the disc is reducedin size.

Additional features and advantages are described herein, and will beapparent from, the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view showing a disc cartridge according to thepresent invention, looking from an upper cartridge half side.

FIG. 2 is a perspective view showing a disc cartridge according to thepresent invention, looking from a lower cartridge half side.

FIG. 3 is a plan view showing a disc cartridge according to the presentinvention, looking from a lower cartridge half side.

FIG. 4 is a perspective view showing a shutter unit and a main cartridgebody unit carrying this shutter unit.

FIG. 5 is a side view showing the lateral side of the disc cartridge ofthe present invention carrying the shutter member.

FIG. 6 is a cross-sectional view showing the state in which the shuttermember is mounted to the main cartridge body unit.

FIG. 7 is a cross-sectional view showing the state in which the aperturefor the head formed in the main cartridge body unit has been closed bythe shutter member.

FIG. 8 is a cross-sectional view showing the state in which the disccartridge of the present invention has been loaded on the recordingand/or reproducing apparatus.

FIG. 9 is a perspective view showing a modification of the disccartridge of the present invention, looking from the upper cartridgehalf side.

FIG. 10 is a perspective view showing another example of a disccartridge of the present invention, looking from the lower cartridgehalf side.

FIG. 11 is a perspective view showing still another example of a disccartridge of the present invention, looking from the upper cartridgehalf side.

FIG. 12 is a perspective view showing the other example of a disccartridge of the present invention, looking from the lower cartridgehalf side.

FIG. 13 is a plan view showing a further example of a disc cartridge ofthe present invention, looking from the lower cartridge half side.

FIG. 14 is a perspective view showing a shutter unit and a maincartridge body unit carrying this shutter unit.

FIG. 15 is a perspective view showing the shutter unit and a shutterlock unit mounted on this shutter unit.

FIG. 16 is a side view showing the lateral side of the disc cartridge,carrying the shutter unit, according to the present invention.

FIG. 17 is a cross-sectional view showing the shutter unit mounted tothe main cartridge body unit.

FIG. 18 is a plan view showing the shutter unit locked by the shutterlock unit.

FIG. 19 is a plan view showing the shutter unit in the unlocked state.

FIG. 20 is a plan view showing the state in which the shutter unit isbeing moved in a direction of opening an aperture for a head unit.

FIG. 21 is a plan view showing the state in which the shutter unit hasbeen moved in a direction of opening the aperture for the head unit.

FIG. 22 is a side view of the disc cartridge showing the opened state ofthe aperture for the head unit.

FIG. 23 is a perspective view showing an example of a disc drive deviceemploying a disc cartridge according to the present invention.

FIG. 24 is a plan view showing the state in which the disc cartridge isbeing inserted with a tilt into a cartridge insertion/ejecting openingof the disc driving unit.

FIG. 25 is a plan view showing the state in which the disc cartridge isbeing inserted with a tilt in the opposite direction into a cartridgeinsertion/ejecting opening of the disc driving unit.

FIG. 26 is a plan view showing the state in which the disc cartridge hasbeen inserted into a cartridge holder with a controlled orientation.

FIG. 27 is a plan view showing the state in which the disc cartridge hasbeen inserted into a cartridge holder to unlock the shutter unit.

FIG. 28 is a plan view showing the state in which the disc cartridge hasbeen inserted into a cartridge holder and the shutter unit has beenmoved to open the recording and/or reproducing aperture.

FIG. 29 is a plan view showing the state in which the disc cartridge hasbeen loaded into a cartridge holder to reproduce the optical disc.

FIG. 30 is a cross-sectional side view showing the state in which anoptical pickup has been moved to the outer rim side of the optical discaccommodated in the disc cartridge loaded on a cartridge loadingsection.

DETAILED DESCRIPTION

The present invention relates to a disc cartridge, having a disc-shapedrecording medium, such as an optical disc, held therein and to arecording and/or reproducing apparatus, employing this disc cartridge asa recording medium.

Referring now to the drawings, a disc cartridge according to the presentinvention is explained in detail.

A disc cartridge 1 according to the present invention houses therein anoptical disc 2, as a disc-shaped recording medium, for rotation therein,and includes a main cartridge body unit 5, made up by upper and lowercartridge halves 3, 4, abutted and bonded together, as shown in FIGS. 1and 2. The optical disc 2 is rotatably housed within this main cartridgebody unit 5.

The disc cartridge 1 according to the present invention houses thereinthe optical disc 2, on which there are recorded program data or videodata for executing e.g. a television game, and is of an extremely smallsize. The present disc cartridge 1 houses therein a small-sized opticaldisc 2 with a diameter on the order of, for example, 60 mm, and is of asize that can be held in a user's palm.

Meanwhile, the optical disc 2, housed in the present disc cartridge 1,is a replay-only disc, having information signals, such as program data,pre-recorded thereon.

The upper and lower cartridge halves 3, 4, making up a main body unit 5,housing the disc cartridge 1, is molded from a synthetic resin material,and upstanding peripheral wall sections 3 a, 4 a are formed on the outerrim of the halves 3, 4, respectively. The upper and lower cartridgehalves 3, 4 are bonded together, with the peripheral wall sections 3 a,4 a abutting to each other, thereby forming the main cartridge body unit5 delimiting a disc housing section 6 therein. The upper and lowercartridge halves 3, 4 are bonded to each other to form the maincartridge body unit 5, by employing a welding technique, such as anultrasonic welding technique, to welding projections formed upright onthe abutting sides and on the sides of the upper and lower cartridgehalves 3, 4 facing each other.

The main cartridge body unit 5, forming the disc cartridge 1 accordingto the present invention, has its front side, as an inserting side endof the disc cartridge 1 into the disc recording and/or reproducingapparatus, formed as an arcuate section 7, as shown in FIGS. 1 to 3.This arcuate section 7 is formed to a semicircle of the optical disc 2of a radius R₁ housed within the disc housing section 6 of the maincartridge body unit 5, with the center of the disc as a center P₀ of thesemicircle, as shown in FIG. 3. That is, the arcuate section 7 is formedas a semicircle commensurate with the semicircle of the optical disc 2housed within the main cartridge body unit 5.

The opposite lateral sides of the main cartridge body unit 5,consecutive to the arcuate section 7 of the main cartridge body unit 5,are formed as sides 8, 9 parallel to each other, while the back side ofthe main cartridge body unit 5, lying opposite to the arcuate section 7,is formed as a uniformly smoothly curved section 10.

With the disc cartridge 1 of the present invention, the front sidethereof, as an inserting side surface, is a substantially semicirculararcuate section 7 of a curvature larger than the other side, oppositethereto, so that, when the disc cartridge is inserted in the slot-instyle via cartridge insertion/ejection opening, the direction ofinsertion into the disc recording and/or reproducing apparatus can beidentified extremely readily. In particular, with the disc cartridge 1,reduced in size so as to be held in the user's palm, the direction ofinsertion can be identified by the sensual touch feeling, thusprohibiting mistaken insertion to enable correct loading on the discrecording and/or reproducing apparatus. Moreover, with the present disccartridge 1, insertion into a slot-in type disc recording and/orreproducing apparatus may be facilitated, while positive insertion maybe assured.

Moreover, the disc cartridge 1 may be further reduced in size, inkeeping with the optical disc 2, accommodated therein, by having theinserting end side formed as a substantially semicircular arcuatesection 7, and by having the back side opposite to the arcuate section 7similarly formed as a curved section 10. At a mid part of the lowercartridge half 4, forming the lower surface of the main cartridge bodyunit 5, there is formed a circular center opening 12 for exposing acenter hole 11 of the optical disc 2 housed in the main cartridge bodyunit 5, and the ambient part thereof, to outside, as shown in FIGS. 2and 3. Into this center opening 12 intrudes a mating engagement portion,such as a turntable, of a disc rotating driving mechanism, provided tothe disc recording and/or reproducing apparatus on which is loaded thedisc cartridge 1.

In the lower cartridge half 4, forming the lower surface of the maincartridge body unit 5, there is formed an aperture for the head part 13,operating as a recording/reproducing aperture. The aperture for the headpart 13 is provided to the lateral side 8 of the main cartridge bodyunit 5, and is formed as a rectangular aperture sized so as to be largeenough to permit a signal recording region of the optical disc 2,accommodated in the main cartridge body unit 5, to be exposed to outsideacross the inner and outer rims of the disc. That is, the aperture forthe head part 13 is formed for being opened in the linear flat lateralside 8 different from the front side of the main cartridge body unit 5carrying the arcuate section 7.

A shutter unit 15 for opening/closing the aperture for the head part 13is movably mounted to the disc cartridge 1. The shutter unit 15 includesa flat-plate-shaped shutter member 16 of a rectangular shape largeenough to close the aperture for the head part 13 and a retention part17 of a U-shaped cross-section formed at the proximal side of theshutter member 16.

The shutter member 15 is formed by punching and warping a thin metalsheet or by shaping a synthetic resin material.

The shutter unit 15 is designed so that the upper cartridge half 3 ofthe cartridge body unit 5 is carried by the retention part 17, so thatthe shutter unit is movable in the directions indicated by arrows A andB for opening/closing the aperture for the head part 13. That is, theshutter unit 15 is mounted for movement on the main cartridge body unit5, by a slide guide 18 being carried by the retention part 17, as shownin FIG. 4. The slide guide 18 is formed by a portion of an upstandingperipheral wall section 3 a of the upper cartridge half 3.

Referring to FIG. 4, the retention part 17, provided to the shutter unit15, is formed with a connecting piece 21, upstanding from the proximalend of the shutter unit 16, and a first engagement piece 22, benttowards the shutter unit 16, is provided to the distal end of theconnecting piece 21. On both sides of the connecting piece 21, a secondengagement piece 23, bent to an L-shape, is formed at a lower positionthan the first engagement piece 22. Meanwhile, the second engagementpiece 23 is bent to an L-shape so that its distal end is protrudedtowards the first engagement piece 22.

The shutter unit 15 is arranged on the main cartridge body unit 5 sothat the shutter member 16 is extended over the aperture for the headpart 13, as shown in FIG. 2. At this time, the shutter unit 15 holds theretention part 17 in a clinching fashion by the first and secondengagement pieces 22, 23, by the first engagement piece 22 of theretention part 17 engaging in an engagement groove 24 formed in thelateral side of the slide guide 18 and by the L-shaped second engagementpiece 23 engaging with the distal end of the slide guide 18, as shown inFIGS. 5 and 6. The shutter unit 15, carried in this manner, is moved inthe directions indicated by arrows A and B for opening/closing theaperture for the head part 13, by being guided by the retention part 17.

The area of the lower cartridge half 4, traversed by the shutter member16, is formed with a recessed shutter slide part 19. This shutter slidepart 19 is formed to a depth D₁ approximately equal to a thickness D₂ ofthe shutter member 16 of the shutter unit 15, as shown in FIG. 7, inorder that the shutter member 16 is not protruded from the surface ofthe main cartridge body unit 5, but is extended on the surface of themain cartridge body unit 5, for flattening out the surface of the maincartridge body unit 5.

A recess 31 is formed in the surface of the lower cartridge half 4, onwhich slides the shutter unit 15 of the main cartridge body unit 5, sothat the recess continues to one side of the aperture for the head part13. This recess 31 operates as an entrance for at least a portion of theoptical pickup forming the head part of the recording and/or reproducingmeans provided to the recording and/or reproducing apparatus. Thisrecess is formed on the opposite side to the shutter slide unit 19 onboth sides of the aperture for the head part 13 and extendssubstantially the whole length of one side of the aperture for the headpart 13, as shown in FIGS. 3 and 7.

The recess 31, into which intrudes the head part, is formed to a depthD₃ larger than the depth D₁ of the shutter slide unit 19, for increasingthe amount of intrusion of the optical pickup forming the head part ofthe recording and/or reproducing means provided on the recording and/orreproducing apparatus, as will be explained subsequently.

The lateral surface of the recess 31 continuing to the aperture for thehead part 13 is formed as an inclined surface section 32, as shown inFIG. 5. This inclined surface section 32 serves for avoiding abutmentagainst a portion of the optical pickup intruding into the recess 31,for example, a portion of the optical block forming the optical pickup.

In the disc cartridge 1 of the present invention, one side of theshutter member 16 of the shutter unit 15, closing the aperture for thehead part 13, is formed with a bent part 34, closing the space definedbetween the shutter member 16 and the recess 31, when the shutter unit15 has moved to a position closing the aperture for the head part 13, asshown in FIG. 7.

Thus, the shutter unit 15, used for the disc cartridge 1 according tothe present invention, is able to close the space defined between theshutter member 16 and the recess 31, when the shutter unit 15 has beenmoved to a position of closing the aperture for the head part 13, asshown in FIG. 7. Consequently, the aperture for the head part 13 may besealed hermetically to prevent dust and dirt from intruding into theinside of the main cartridge body unit 2 through the aperture for thehead part 13 to assure reliable protection of the optical disc 5accommodated in the main cartridge body unit 2.

In the disc cartridge 1 of the present invention, a cut-out 25 is formedin a region of the upstanding peripheral wall section 4 a of the lowercartridge half 4 facing the aperture for the head part 13, as shown inFIGS. 2 and 4. That is, the aperture for the head part 13 serves forexposing an area of the main cartridge body unit 5 extending from theinner rim up to the outer rim of the main cartridge body unit 5.

When the disc cartridge 1 of the present invention, constructed asdescribed above, is loaded on the recording and/or reproducingapparatus, a portion of the optical pickup 51, forming a head part forreproducing the information signals, recorded on the optical disc 2, maybe introduced into the recess 31, as shown in FIG. 8.

Within the recording and/or reproducing apparatus, in which is loadedthe disc cartridge 1 according to the present invention, there isprovided a cartridge loading section, not shown, for loading the disccartridge 1 in position. Within the recording and/or reproducingapparatus, there are provided a disc rotation driving mechanism forrotationally driving the optical disc 2 accommodated in the disccartridge 1 loaded on the cartridge loading section, and an opticalpickup 51 forming the head part for scanning the signal recording areaof the optical disc 2 rotationally driven by the disc rotation drivingmechanism for reproducing the information signals. This optical pickup51 includes an optical block 52, having enclosed therein a light sourcefor radiating a light beam for scanning the signal recording area of theoptical disc 2, optical components for routing the light beam, emanatedfrom the light source, to the optical disc 2, and a light sourceconverter for detecting the return light beam reflected back from thelight source for detecting data recorded on the optical disc 2, and abi-axial actuator 54 having an objective lens 53 for condensing thelight beam, radiated from the light source, to the signal recordingsurface of the optical disc 2.

This optical pickup 51 is carried by a slide guide shaft 55 and a guide56, arranged parallel to each other in the recording and/or reproducingapparatus, so as to be movable along the radius of the optical disc 2housed in the disc cartridge 1 loaded on the cartridge loading unit. Theoptical pickup 51 is arranged at this time so that the objective lens 53faces the aperture for the head part 13 provided in the disc cartridge 1and so that the optical block 52 is placed laterally of the aperture forthe head part 13.

If, in the present recording and/or reproducing apparatus, the opticaldisc 2 is to be reproduced, the objective lens 53 may intrude via theaperture for the head part 13 into the inside of the main cartridge bodyunit 5, so that part of the optical block 52 may intrude into the recess31 of the disc cartridge 1, as shown in FIG. 8. The result is that theoptical pickup 51 in its entirety may be caused to approach to the disccartridge 1, loaded on the cartridge loading unit, and hence theapparatus in its entirety may be reduced in thickness.

The arrangement is effective in particular for a recording and/orreproducing apparatus employing a disc cartridge 1 having housed thereinan optical disc 2 having a diameter equal to 60 mm or less. With thesmall-sized disc cartridge 1, the aperture for the head part 13 is alsosmall-sized, such that the optical pickup 51 in its entirety cannot beintroduced into the inside of the main cartridge body unit 5. Inparticular, the optical pickup 51, made up by the optical block 52 andthe bi-axial actuator 54, cannot be reduced in size further because ofits structure.

With the use of the disc cartridge 1, according to the presentinvention, the optical pickup 51, which is difficult to reduce in sizein keeping with the reduction in size of the disc cartridge 1, can becaused to approach to the disc cartridge 1 loaded on the cartridgeloading section. That is, the optical pickup 51 may be arranged as theoptical block 52 is partially intruded into the recess 31 formed in thedisc cartridge 1.

Since the optical pickup 51 may be made to approach to the disccartridge 1, the recording and/or reproducing apparatus, employing thedisc cartridge 1, may be reduced in thickness.

Although the above-described disc cartridge 1 is provided with theshutter unit 15 for closing the aperture for the head part 13, theaperture for the head part may be left in the opened state, withoutproviding the shutter unit.

The disc cartridge 101 not having the shutter unit is configured asshown in FIGS. 9 and 10.

Similarly to the disc cartridge 1, a disc cartridge 101, not having theshutter unit, includes a main cartridge body unit 5, comprising an uppercartridge half and a lower cartridge half, abutted and connected to eachother, and the optical disc 2 is rotationally mounted in this maincartridge body unit 5.

Referring to FIGS. 9 and 10, the forward surface, as a lateral surfaceas an inserting end into the disc recording and/or reproducingapparatus, into which the disc cartridge 101 is introduced, is formed asan arcuate section 7, as shown in FIGS. 9 and 10.

The opposite lateral sides of the main cartridge body unit 5, continuingto the arcuate section 7 of the main cartridge body unit 5, are formedas lateral sides 8, 9 not parallel to each other, while the back sidethereof, opposite to the arcuate section 7, is formed as a smoothlycurved continuous curved surface 10. That is, the back surface of themain cartridge body unit 5, is formed as a curved portion 10 having aradius larger than the radius of the semi-circular arcuate section 7formed on the forward side of the main cartridge body unit 5.

With this disc cartridge 101, a center opening 11 formed centrally ofthe optical disc 2 housed in the main cartridge body unit 5, and acircular center recess 12 for exposing the rim part of the centeropening 11, are formed centrally of the lower cartridge half 4, as shownin FIG. 10.

In the lower cartridge half 4, an aperture for the head part 113, as arecording and/or reproducing aperture, is formed, as shown in FIG. 10.The aperture for the head part 113 is formed on one lateral surface 8 ofthe main cartridge body unit 5, and is formed to a rectangular profilefrom a position proximate to the circular center recess 12 up to thelateral side 8. That is, the aperture for the head part 113 is formed toa rectangular profile of a size large enough to expose a part of thesignal recording area of the optical disc 2, housed in the maincartridge body unit 5, to be exposed to outside across the inner andouter rims of the disc.

The lower cartridge half 4 is also provided with an entrance aperturefor the head part 131, continuing to the aperture for the head part 113formed in the disc cartridge 101 of the present embodiment. Into thisentrance aperture for the head part 131 may be introduced at least aportion of the optical pickup forming the head part of the recordingand/or reproducing means provided to the recording and/or reproducingapparatus. This entrance aperture for the head part 131 is formed incontinuation to one side of the aperture for the head part 113 towardsthe arcuate section 7 operating as an inserting end into the recordingand/or reproducing apparatus of the main cartridge body unit 5. That is,with the disc cartridge 101 of the present embodiment, the entranceaperture for the head part 131 is formed, such as by enlarging the sideof the aperture for the head part 113 towards the arcuate section 7 ofthe main cartridge body unit 5.

With this disc cartridge 101, the optical block 52, making up theoptical pickup 51, scanning the optical disc 2 of the disc recordingand/or reproducing apparatus, may be introduced into the entranceaperture for the head part 131. The result is that the optical pickup 51in its entirety may be brought to close to the disc cartridge 1, loadedon the cartridge loading section of the recording and/or reproducingapparatus, and hence the recording and/or reproducing apparatus in itsentirety may be reduced in thickness.

In this disc cartridge 101, a lateral surface of the entrance aperturefor the head part 131 is formed as an inclined surface section 132 forevading abutment against a portion of the optical pickup 51, forexample, the optical block 52 of the optical pickup 51.

In the disc cartridge 101, not having the shutter member, the aperturefor the head part may be formed as a recess, as in the disc cartridge 1.

The disc cartridges 1, 101 are formed as having housed therein areplay-only optical disc 2. However, the disc cartridge according to thepresent invention may similarly be applied to a disc cartridge havinghoused therein a recording and/or reproducing optical disc or the likedisc-shaped recording medium with similar favorable results.

It is noted that the recording and/or reproducing apparatus, employingthe disc cartridge according to the present invention, uses a head partwhich differs from one sort of the disc-shaped recording medium toanother. Referring to the drawings, a disc cartridge 201 according to amodification of the present invention is now explained.

Similarly to the above disc cartridge, the present disc cartridge 201has housed therein e.g. an optical disc 2, as a disc-shaped recordingmedium. The disc cartridge 201 includes a main cartridge body unit 5,obtained by abutting together and combining the upper and lower halves3, 4, as shown in FIGS. 11 and 12. The optical disc 2 is housed forrotation in the inside of the main cartridge body unit 5.

For the following explanation, common reference numerals are used fordepicting the components used in common with the disc cartridge 1.

The disc cartridge 201 has housed therein an optical disc 2, havingrecorded thereon program data or video data for playing the televisiongame, and is of an extremely small size.

The main cartridge body unit 5, forming the disc cartridge 201 accordingto the present invention, has its front side, as an inserting side endof the disc cartridge 1 into the disc recording and/or reproducingapparatus, formed as an arcuate section 7, as shown in FIGS. 1 to 3.This arcuate section 7 is formed to a semicircle of the optical disc 2of a radius R₁ housed within the disc housing section 6 of the maincartridge body unit 5, with the center of the disc as a center P₀ of thesemicircle, as shown in FIG. 3. That is, the arcuate section 7 is formedas a semicircle commensurate with the semicircle of the optical disc 2housed within the main cartridge body unit 5.

The opposite lateral sides of the main cartridge body unit 5,consecutive to the arcuate section 7 of the main cartridge body unit 5,are formed as sides 8, 9, extending parallel to each other, while theback side of the main cartridge body unit 5, lying opposite to thearcuate section 7, is formed as a uniformly smoothly curved section 10.

At a mid part of the lower cartridge half 4, forming the lower surfaceof the main cartridge body unit 5, there is formed a circular centeropening 12 for exposing a center hole 11 of the optical disc 2 housed inthe main cartridge body unit 5, and the ambient part thereof, tooutside, as shown in FIGS. 2 and 3. At a mid part of the lower cartridgehalf 4, forming the lower surface of the main cartridge body unit 5,there is formed an aperture for the head part 13, as a recording and/orreproducing aperture, as shown in FIGS. 2 and 3. The aperture for thehead part 13, formed in one lateral surface of the main cartridge bodyunit 5, is formed to a rectangular profile large enough to permit aportion of the signal recording area of the optical disc 2 to be exposedto outside across the inner and outer rims of the disc. That is, theaperture for the head part 13 is formed facing the rectilinear planarlateral surface 8 other than the forward surface of the main cartridgebody unit 5 formed with the arcuate section 7.

To the disc cartridge 201 according to the present invention, there ismounted a shutter unit 215 configured for opening/closing the aperturefor the head part 13. The shutter unit 215 includes a rectangularflat-plate-shaped shutter member 216 large enough to close the aperturefor the head part 13 and a retention part 217 of a U-shapedcross-section formed towards the substrate of the shutter member 216.

The shutter unit 215 has its part towards the upper cartridge half 3 ofthe main cartridge body unit 5 carried by the retention part 217 and, inthis state, is carried for movement in the direction indicated by arrowsA and B in FIG. 12 for opening/closing the aperture for the head part13. That is, the shutter unit 215 is mounted for movement to the maincartridge body unit 5 in such a manner that a slide guide 18, formed bya portion of an upstanding peripheral wall section 3 a of the uppercartridge half 3, is carried by the retention part 217, as shown in FIG.14.

The retention part 217, provided to the shutter unit 215, is formed witha connecting piece 221, formed upright from the proximal end of theshutter member 216, and a first engagement piece 222, bent towards theshutter member 216, is provided to the distal end of the connectingpiece 221, as shown in FIGS. 14 and 15. On both sides of the connectingpiece 221, there are formed second engagement pieces 223 bent to an Lshape at a lower level than the first engagement piece 222. The distalends of the second engagement pieces 223 are bent to the L shape, withthe distal ends thereof protruding towards the first engagement piece222.

This shutter unit 215 is provided to the main cartridge body unit 5, sothat the shutter member 216 extends over the aperture for the head part13, as shown in FIG. 12. At this time, the first engagement piece 222provided to the retention part 217 of the shutter unit 215 is engaged inan engagement groove 24 formed in the lateral surface of the slide guideunit 18, while the L-shaped second engagement pieces 223 are engagedwith the distal end of the slide guide 18, whereby the shutter unit 1215carries the retention part 17 by clenching it between the first andsecond engagement pieces 222, 223, as shown in FIGS. 16 and 17. Theshutter unit 215, thus carried, is moved in the directions of arrows Aand B in FIG. 12, for opening/closing the aperture for the head part 13in FIG. 12, as the shutter unit is guided by the retention part 217.

In an area of the lower cartridge half 4, traversed by the shuttermember 216, there is formed a recessed shutter slide unit 19. Thisshutter slide unit 19 is formed to a depth sufficient not to permit theshutter member 216 to emerge from the upper surface of the maincartridge body unit 5.

Referring to FIGS. 14 and 17, a cut-out 25 is formed in an area of theupstanding peripheral wall section 4 a of the lower cartridge half 4 ofthe disc cartridge 201 of the present invention. That is, the area ofthe aperture for the head part 13 extending from the inner rim up to theouter rim of the main cartridge body unit 5 is opened.

At least the part of the slide guide 18 of the upper cartridge half 3facing the aperture for the head part 13 is of a height H₁ not protrudedfrom the lower surface 2 a of the optical disc 2, facing the lowercartridge half 4, when the optical disc 2, loaded in the disc cartridge1 in position, as to the height, on the cartridge loading section in thedisc recording and/or reproducing apparatus, is loaded on the turntable,as shown in FIG. 17.

With the above-described disc cartridge 201, when the shutter unit 215is moved to open the aperture for the head part 13, the optical pickup,as a head part for reading out the information signals recorded on theoptical disc 2, may be located in its entirety within the main cartridgebody unit 5. In addition, when the optical pickup has been moved to aposition scanning the outer rim of the optical disc 2, the opticalblocks other than an objective lens, converging the light beam, used forscanning the signal recording area of the optical disc 2, may be locatedoutside the main cartridge body unit 5, as the objective lens is locatedwithin the main cartridge body unit 5, as will be explainedsubsequently.

Hence, with the disc cartridge 201 of the present invention, the opticalpickup may be located across the inner part and an outer part of themain cartridge body unit 5, as the optical pickup is proximate to theoptical disc 2. Thus, the signal recording area may be formed up to theouter rim of the optical disc 2, thereby increasing the recordingcapacity of the optical disc 2. Moreover, since the optical pickup maybe proximate to the optical disc 2, the numerical aperture NA of theobjective lens may be larger, while the spot of the light beam condensedon the optical disc 2 may be smaller, thereby increasing the recordingdensity of the information signals recorded on the optical disc 2. Sincethe recording density may be improved with increase in the recordingcapacity, the optical disc in need of a preset recording capacity may bereduced in diameter. Since the optical disc 2 may be scanned as theoptical pickup is positioned for movement across the inner and outerparts of the main cartridge body unit 5, the main cartridge body unit 5may be reduced in size, whilst the disc recording and/or reproducingapparatus, employing the disc cartridge 201, may also be reduced insize.

In the surface of the lower cartridge half 4 of the main cartridge bodyunit 5, on which slides the shutter unit 15, there is further formed arecess 31 in continuation to one side of the aperture for the head part13. This recess 31 operates as an entrance for at least a portion of theoptical pickup forming the head part of the recording and/or reproducingmeans, provided to the recording and/or reproducing apparatus. Therecess is positioned facing the shutter slide 19, on both sides of theaperture for the head part 13, and is formed for extending the entirelength of one lateral side of the aperture for the head part 13, asshown in FIGS. 12 and 16.

By providing this recess 31, the part of the optical pickup, forming thehead part used for reproducing information signals recorded on theoptical disc 2 may be introduced into the recess 31 when the disccartridge 201 is loaded on the recording and/or reproducing apparatus.Hence, the optical pickup may be brought into proximity of the disccartridge 201, so that the recording and/or reproducing apparatus may bereduced in thickness.

In the disc cartridge 201, according to the present invention, theshutter unit 215, opening/closing the aperture for the head part 13, ismounted for movement along the flat lateral surface 8 of the maincartridge body unit 5, as shown in FIGS. 11 and 12. Thus, the shutterunit 215 is moved linearly with the retention part 217 contacting withthe planar lateral surface 8, and hence may be moved in stability.

Moreover, since the aperture for the head part 13 is formed facing theflat lateral surface 8 of the main cartridge body unit 5, the portion ofthe lower cartridge half 4 formed with the cut-out 25 is also arectilinear surface. Hence, even if the cut-out 25 is formed in thelower cartridge half and the lateral surface 8 of the main cartridgebody unit 5 facing outwards is opened, the aperture for the head part 13may be formed in its entirety to a rectangular profile and maypositively be closed by the shutter unit 215 having the rectilinearretention part 217 of a U-shaped cross-section.

The disc cartridge 1 according to the present invention is provided witha lock unit 227 for prohibiting the movement of the shutter unit 215when the shutter unit 215 has been moved to a position closing theaperture for the head part 13. The lock unit 227 of the shutter unit 215includes a lock lever 228, mounted for rotation to the shutter unit 215,and an engagement part 229 on the main cartridge body unit 5, engaged bythis lock lever 228, as shown in FIGS. 15 and 18.

The lock lever 228 is formed as an elongated plate-shaped member,including an upstanding thrust part 230, extending along a lateral sideedge thereof, and an upstanding engagement piece 231 on the oppositeside for engagement by the engagement part 229, as shown in FIGS. 15 and18. The lock lever 228 is rotationally mounted on a lock lever mountingpiece 232 provided to the shutter unit 15. The lock lever mounting piece232 is formed for protruding laterally of the shutter member 216 fromthe upper edge of the connecting piece 221 forming the slide guide 18 ofthe shutter unit 215.

The lock lever 228 is rotatably mounted about a pivot 235, mounted inturn upright on the lock lever mounting piece 232, as the center ofrotation, so that the thrust part 230 at one end thereof faces arectangular window 233 formed at a mid portion of the connecting piece221, with a pivot hole 234 at a mid part of the connecting piece 221 inengagement by the pivot 235, as shown in FIGS. 11, 16 and 18. At thistime, the engagement piece 231, provided to the opposite side of thelock lever 228, is protruded laterally of the shutter member 216 forextending along the lock lever mounting piece 232.

A window 233 formed in the connecting piece 221 of the shutter unit 215is engaged by a shutter unit movement inhibiting spring, provided forinhibiting movement of the shutter unit 215, provided to the discrecording and/or reproducing apparatus, to which the disc cartridge 1 ismounted.

The lock lever 228, carried by the shutter unit 215, is rotationallybiased by a rotational force energizing spring 237, coiled about thepivot 35, in a direction shown by an arrow C in FIG. 8 for protrudingthe thrust part 230 from the window 233. The rotational force energizingspring 237 is formed by a torsion coil spring, and has one arm section237 a retained by the thrust part 230, while having the other armsection 237 b retained by the inner surface of the connecting piece 221of the shutter unit 215, for rotationally biasing the lock lever 228 inthe direction indicated by arrow C in FIG. 8.

The rotational position of the lock lever 228 by the rotational forceenergizing spring 237 is determined by abutment of the side of the locklever 228 carrying the thrust part 230 against the connecting piece 221.

The shutter unit 215, carrying the lock lever 228 as described above, ismounted for movement to the main cartridge body unit 5, by having theretention part 217 carried by the upper cartridge half 3, as describedabove.

When the shutter unit 215 is at a position of closing the aperture forthe head part 213, as shown in FIGS. 16 and 18, the lock lever 228 isrotated in the direction of arrow C in FIG. 18, under the biasing forceof the rotational force energizing spring 237, for introducing thethrust part 230 into the window 233 formed in the connecting piece 221.At this time, the lock lever 228 inhibits movement of the shutter unit215, by the engagement piece 231 at the opposite end thereof engagingwith a mating engaging part 229, provided to the main cartridge bodyunit 5. The lock lever also operates for retaining the aperture for thehead part 13 in a closed state by the shutter unit 216.

The mating engaging part 229 of the main cartridge body unit 5 isprovided to an area of the inner surface of the lower cartridge half 4,outside the area of the disc housing section 6, which may be engaged bythe engagement piece 231 of the lock lever 228 when the shutter unit 215is in the closure position. The mating engaging part 229 is formed asone with the lower cartridge half 4. The mating engaging part 229 isformed with an engagement recess 229 a opened on one side. In thisengagement recess 229 a is introduced the engagement piece 31 providedto the lock lever 228.

When the disc cartridge 201 is introduced into the disc recording and/orreproducing apparatus, the lock lever 228, which has locked the shutterunit 215 in the closure position, is rotated in the direction indicatedby arrow D in FIG. 18, against the bias of the rotational forceenergizing spring 237, by the thrust part 230 being thrust by theshutter unit movement inhibiting spring intruding into engagement withthe window 233 formed in the connecting piece 221. When the lock lever228 is rotated in the direction of the arrow D in FIG. 18, theengagement piece 231 is disengaged from the engagement recess 229 a ofthe mating engaging part 229, as shown in FIG. 19, for detaching theengagement piece 231 from the engagement recess 229 a of the matingengaging part 229, thereby unlocking the shutter unit 215. The shutterunit 215 may now be movable along the direction of the arrow A in FIG.12, that is, in a direction of opening the aperture for the head part13.

Meanwhile, the opening/closure of the aperture for the head part 13 isby relative movement between the main cartridge body unit 5 and theshutter unit 215. The opening/closure of the aperture for the head part13 will be explained in detail subsequently.

With the above-described lock unit 27 for the shutter unit, in which thelock lever 228, locking the shutter unit 215 in the closure position, ismounted to the shutter unit 215, movable with respect to the maincartridge body unit 5, the lock lever may be moved in unison with theshutter unit 215 to follow up with the opening/closure of the aperturefor the head part 13. As a result, the lock lever 228 may be placed suchthat, when the shutter unit 215 is in the position of closing theaperture for the head part 13, at least the thrust part 230 overlies theaperture for the head part 13, thus enabling the size of the disccartridge 1 to be reduced. That is, in case the lock lever 228 isprovided to the main cartridge body unit 5, it should be necessary toprovide the space, in which to arrange the lock lever 228 in itsentirety, to the main cartridge body unit 5. This necessity may beeliminated with the disc cartridge 1 of the present invention, such thatit is only sufficient to provide solely the mating engaging part 229,engaged by a portion of the lock lever 228, on the main cartridge bodyunit 5, with the consequence that the main cartridge body unit 5 mayfurther be reduced in size.

The disc cartridge 201, according to the present invention, may furtherbe provided with a shutter opening/closure unit 238 realizing thereliable movement of the shutter unit 15 opening/closing the aperturefor the head part 13 and which positively holds the shutter unit 215 inthe position of opening or closing the aperture for the head part 13.

This shutter opening/closure unit 238 is formed using a bi-directionalenergizing unit for selectively energizing the shutter unit 215 intomovement in two directions, viz. in a direction of opening the aperturefor the head part 213 and in a direction of closing the aperture for thehead part. Specifically, the bi-directional energizing unit is formed bya torsion coil spring 239, as shown in FIG. 18. This torsion coil spring239, mounted between the shutter unit 215 and the main cartridge bodyunit 5, is arranged at a location towards which the shutter unit 215 ismoved in the direction of opening the aperture for the head part 13, asshown in FIG. 18. Specifically, the torsion coil spring 239 is mountedby engaging the distal end of an arm section 239 a in an engagementopening 240 formed in the distal end of the lock lever mounting piece232 and by engaging a ring 241 at the distal end of the other armsection 239 b by a support pin 242 protuberantly formed on the innersurface of the main cartridge body unit 5.

When the torsion coil spring 239 is at the position of closing theaperture for the head part 13, the torsion coil spring 239 biases theshutter unit 215 in the direction indicated by the arrow B in FIG. 18for retaining the state of closing the aperture for the head part 13.When the disc cartridge 201 is loaded on the disc recording and/orreproducing apparatus, and the shutter unit 215, released from thelocked state by the lock unit 227 for the shutter unit, is movedrelative to the main cartridge body unit 5 in the direction of the arrowA in FIG. 18 for opening the aperture for the head part 13, a coil part239 c, formed centrally of the spring in an unfixed state, is moved inthe direction of arrow A, along which is moved the shutter unit 215.When the coil part 239 c of the torsion coil spring 239 is further movedalong the direction of the arrow A and is moved beyond the location of asupport pin 242, along the direction of movement of the shutter unit 15,as shown in FIG. 20, the biasing direction is reversed. On reversion ofthe biasing direction, the torsion coil spring 239 biases the shutterunit 215 into movement along the arrow A in FIG. 20. Thus, the shutterunit 215 is moved in a direction of opening the aperture for the headpart 13, to retain the aperture for the head part 13 in the openedposition, as shown in FIGS. 21 and 22.

When the disc cartridge 201, in a state in which the shutter unit 215retains the aperture for the head part 13 in the opened position, istaken out from the disc recording and/or reproducing apparatus, by wayof performing the operation for ejection, the shutter unit 215 is movedalong the direction of arrow B in FIG. 20, relative to the maincartridge body unit 5, with the center coil part 239 c being similarlymoved along the direction of arrow B. When the shutter unit 215 isfurther moved along the direction of arrow B, such that it surpasses thelocation of the support pin 242 along the direction of movement of theshutter unit 215, the biasing direction is reversed. On reversion of thebiasing direction, the torsion coil spring 239 biases the shutter unit215 into movement along the arrow B in FIG. 19, such that the shutterunit 215 is moved in the direction of closing the aperture for the headpart 213, thereby retaining the aperture for the head part in the closedstate.

The shutter unit 215, biased by the torsion coil spring 239, forming thebi-directional energizing unit, is carried in the position of closingthe aperture for the head part 13 or in the position of opening theaperture for the head part 13, under the biasing force of the torsioncoil spring 239, and hence may be maintained reliably in the position ofclosing or opening the aperture for the head part 13.

In the disc cartridge 201, according to the present invention, providednot only with the lock unit 227 for the shutter unit, locking theshutter unit 215 in the closed position, but also with the shutteropening/closure unit 238, having the bi-directional energizing unit forselectively biasing the shutter unit 215 in the two directions, theshutter unit 215 may be reliably retained in the position of closing theaperture for the head part 13, while the reliable opening/closureoperation for the aperture for the head part 13 may be achieved.

For reliably closing the aperture for the head part 13, it is onlysufficient to provide the lock unit 227 for the shutter unit. Forrealizing a stable opening/closure movement of the shutter unit 215,maintaining the closed state of the aperture for the head part 13, andfor reliably maintaining the opened state of the aperture for the headpart 13, it is possible to provide only the shutter opening/closure unit238 having the bi-directional energizing unit.

In the disc cartridge 201, according to the present invention, thelateral surface 8 of the main cartridge body unit 5, carrying theshutter unit 215, is formed with a guide groove 49, into which intrudesa shutter unit releasing piece, provided to the disc recording and/orreproducing apparatus, as shown in FIGS. 11, 16 and 22.

In the lower surface of the main cartridge body unit 5, on both sides ofthe back surface thereof, forming the curved section 10, there areformed first and second positioning holes 43, 44, engaged by positioningpins, provided to the disc recording and/or reproducing apparatus, asshown in FIGS. 12 and 13. Meanwhile, the second positioning hole 44 isformed as an elongated hole, having the width-wise direction, lying atright angles to the direction of movement of the shutter unit 15, as along radius.

On both lateral sides 8, 9 of the arcuate section 7 of the maincartridge body unit 5, there are provided engagement recesses 45, 46,engaged by a portion of a cartridge loading unit, provided to therecording and/or reproducing apparatus for loading the disc cartridge201 thereon, as shown in FIGS. 11 and 12.

In a location proximate to the opposite lateral side 9 of the arcuatesection 7 of the main cartridge body unit 5, there is provided anengagement recess 47 for ejection, engaged by a portion of an ejectionunit provided to the recording and/or reproducing apparatus, as shown inFIG. 12.

In the lateral sides 8, 9 or in the bottom surface of the cartridge mainbody unit 5, a discriminating opening or a discriminating recess foridentifying the sort of the optical disc 2 is provided as necessary.

An embodiment of the disc recording and/or reproducing apparatus,employing the disc cartridge 201, according to the present invention, ishereinafter explained.

In the disc cartridge 201, according to the present invention, there ishoused the optical disc 2, having recorded thereon the program data orvideo data needed for executing e.g. a TV game. The disc recordingand/or reproducing apparatus, employing the disc cartridge 201 of thepresent invention, housing this sort of the optical disc 2, is made upby a main body unit of the apparatus 251, carrying the disc cartridge 1,and having enclosed therein a disc driving unit for reproducing at leastdata recorded on the optical disc 2, and by a display 252 fordemonstrating image data or text data reproduced from the optical disc2, as shown in FIG. 23.

Within the main body unit of the apparatus 251 of a disc driving device250, having enclosed therein the disc driving unit, shown in FIG. 23,there is provided a cartridge loading unit, not shown, including acartridge holder for loading the disc cartridge 201 thereon. In thefront surface, forming one of the lateral sides of the main body unit ofthe apparatus 251, there is formed a cartridge inserting/ejectingopening 253 for inserting the disc cartridge 201 into a cartridge holderand for ejecting the disc cartridge 201 loaded in the cartridge holder.The cartridge inserting/ejecting opening 253 is formed as an openingjust large enough to permit insertion/removal of the disc cartridge 201,and has a width W₂ and a height H₂ slightly larger than the width W₁ anda thickness D₁, respectively, of the disc cartridge 201 insertedtherein. Within the main body unit of the apparatus 251, there isarranged a cartridge holder 254 facing the cartridge inserting/ejectingopening 253.

On one side of the front surface of the main body unit of the apparatus251, there is mounted an ejection button 255 for ejecting the disccartridge 201 held by the cartridge holder 254.

On one side of the upper surface of the main body unit of the apparatus251, there are provided actuating buttons 256, 257 of a control switch,used for carrying out e.g. a TV game. On the other side thereof, acontrol key 258 for scrolling the image demonstrated on the display 252.There is also provided a loudspeaker 259 for radiating audio signalsreproduced from the optical disc 2.

Although not shown, a control bobbin for e.g. a reproducing button, forcontrolling the disc driving unit, and an actuating button for a powersupply switch, are provided to the main body unit of the apparatus 251.

The display 252 is provided on the back side, opposite to the frontside, carrying the cartridge inserting/ejecting opening 253 of the mainbody unit of the apparatus 251, for swinging relative to the main bodyunit of the apparatus 251 via a hinge unit 260. The display 252 may beswung towards the main body unit of the apparatus 251 so as to besuperposed on the upper surface thereof. The display 252 is formed by aliquid crystal display panel.

The state in which the disc cartridge 201 according to the presentinvention is loaded on the disc driving unit 250, constructed asdescribed above, is hereinafter explained.

For loading the disc cartridge 201 on the disc driving device 250, thedisc cartridge 201 is inserted via the cartridge inserting/ejectingopening 253 into the main body unit of the apparatus 51, with thearcuate section 10 as the inserting side, so as to be held on thecartridge holder 254, as shown in FIG. 23.

Meanwhile, with the disc cartridge 201 according to the presentinvention, the inserting end thereof via the cartridgeinserting/ejecting opening 253 is formed as the approximatelysemicircular arcuate section 7, so that, even when the disc cartridge 1is inserted with a centerline P₂ along the widthwise direction of thedisc cartridge significantly inclined with respect to the centerline P₁along the width-wise direction of the cartridge inserting/ejectingopening 253, the disc cartridge can be smoothly inserted into thecartridge inserting/ejecting opening 253 and reliably held by thecartridge holder 254.

That is, the disc cartridge 201, having the inserting end formed as theapproximately semicircular arcuate section 7, may be inserted into themain body unit of the apparatus 251 at the approximately semicirculararcuate section 7, even in case the disc cartridge is inserted via thecartridge inserting/ejecting opening 253 with the width-wise centerlineP₂ inclined by an angle up to approximately 45° towards left or right ofthe width-wise centerline P₁ of the cartridge inserting/ejecting opening253, as shown in FIG. 24 or 25. At this time, the disc cartridge 201 maybe corrected in its orientation by rotating it in a direction causingthe coincidence of the centerlines P₁ and P₂, in the course of theinsertion thereof through the cartridge inserting/ejecting opening 253,with the portion of the arcuate section 7, abutting against one of thelateral sides of the cartridge inserting/ejecting opening 253, as thecenter of rotation, as shown in FIG. 26. Thus, the disc cartridge 1,according to the present invention, may reliably be inserted into thecartridge holder 254, even in case the inserting direction thereofthrough the cartridge inserting/ejecting opening 253 is inclinedsignificantly.

The disc cartridge 201, inserted into the cartridge holder 254, isfurther introduced into the cartridge holder 254, whereby the shutterunit 215 is moved relative to the main body unit of the apparatus 251 toopen the aperture for the head part 13. That is, when the disc cartridge201 has been introduced halfway in the cartridge holder 254, as shown inFIG. 27, a portion of a shutter unit movement inhibit spring 62, formedby segmenting a part of the sidewall section of an L-shaped cartridgeretention part 261 in one lateral side of the cartridge holder 254,intrudes into the window 233 formed in the connecting piece 221 of theshutter unit 215, thereby thrusting the thrust part 230 to causerotation of the lock lever 228 in the direction indicated by arrow D inFIG. 19, as described previously. When rotated in the directionindicated by arrow D in FIG. 19, the lock lever 228 is disengaged fromthe mating engaging part 229 of the engagement piece 231 to release thelock of the shutter unit 215 with respect to the main cartridge bodyunit 5. When unlocked from the main cartridge body unit 5, the shutterunit 215 is movable relative to the main cartridge body unit 5.

The cartridge holder 254, on which is loaded the disc cartridge 1according to the present invention, is further provided with a shutterreleasing piece 63. This shutter releasing piece 63 intrudes into aguide groove 49, formed in the lateral surface 8 of the main cartridgebody unit 5, until it abuts against the lateral side of the shutter unit215.

When inserted into the inside of the cartridge holder 254, untilunlocking of the shutter unit 215, the shutter releasing piece 263 abutsagainst the lateral side of the shutter unit 215, to inhibit themovement of the shutter unit 215 relative to the main cartridge bodyunit 5, as shown in FIG. 27. When the disc cartridge 1 further intrudesfrom the position shown in FIG. 27 towards the inner part of thecartridge holder 254, in the direction indicated by arrow E, the maincartridge body unit 5 is moved along the direction as indicated by arrowE, thereby opening the aperture for the head part 13, as shown in FIG.28.

If, as the movement of the shutter unit 215 is inhibited, the disccartridge 201 is moved in the direction indicated by arrow E in FIG. 27,with the main cartridge body unit 5 then opening the aperture for thehead part 13, the torsion coil spring 239, forming the shutteropening/closure unit 238, is biased, as described above with referenceto FIGS. 19 and 20. When the main cartridge body unit 5 is moved in thedirection indicated by arrow E in FIG. 27, such that the coil part 239 csurpasses the location of the support pin 242, lying along the directionof movement of the shutter unit 215, thus biasing the torsion coilspring 39, the biasing direction of the torsion coil spring 239 isreversed. The shutter unit 215 is then moved in the direction of arrow Fin FIG. 27, opposite to the direction of movement of the main cartridgebody unit 5, thus opening the aperture for the head part 13, as shown inFIGS. 11, 21 and 28. At this time, the shutter unit 215 is biased by thetorsion coil spring 239 for opening the aperture for the head part 13,thus reliably retaining the aperture for the head part 13 in the openedstate.

The disc cartridge 201, inserted into the cartridge holder 254, with theaperture for the head part 13 opened by the above-described operation,is loaded in position on the cartridge loading section, provided in thedisc driving device 250. At this time, the optical disc 2 is loaded inposition in a disc driving unit. This disc driving unit is then actuatedto reproduce the program data recorded on the optical disc 2 to run theprogram.

For ejecting the disc cartridge 1, loaded on the disc driving device250, after reproducing the optical disc 2, an ejection button 255 ispressed. On pressing the ejection button 255, the disc cartridge 1,loaded on the cartridge loading section, is ejected. After the ejectionoperation is carried out, the shutter unit 215 is moved relative to themain cartridge body unit 5 to revert to the initial position of closingthe aperture for the head part 13 to lock the shutter unit 215 in thisposition of closing the aperture for the head part 13, by the reverse ofthe operation, described above. By this operation of restoring theshutter unit 215 to the closure position, the disc cartridge is ejectedvia the cartridge loading/unloading opening 253, so that the ejection ofthe disc cartridge 201, loaded on the disc driving device 250, comes toa close.

The state in which the disc cartridge 201 according to the presentinvention is loaded on the disc drive device 250 is further explained.The disc cartridge 201 is loaded on the cartridge loading section 67,provided in the main cartridge body unit 51, with the lower surfacethereof as a loading surface, as shown in FIG. 29. In this lower surfaceof the disc cartridge, there is formed a disc driving opening 12 inwhich is inserted a turntable 66 forming the disc rotating driving unit65 provided in the disc drive device 250.

Meanwhile, the cartridge loading section 67 is mounted on a base 69carrying a disc rotating driving unit 65 and an optical pickup 68 forreproducing the data recorded on the optical disc 2. The cartridgeloading section 67 is provided with a positioning pin 70 for positioningthe disc cartridge 1 in the planar direction and a positioning lug, notshown, for positioning the disc cartridge 201 in the height-wisedirection. The disc cartridge 201 is loaded on the cartridge loadingsection 67, as it is positioned in the planar and height-wisedirections, by the positioning pin 70 engaging in each of the first andsecond positioning holes 43, 44 and by the lower surface being supportedby the height positioning lug.

With the disc cartridge 201 of the present invention, the portion facingthe aperture for the head part 13 of the upstanding peripheral wallsection 4 a of the lower cartridge half 4 is formed with the cut-out 25and thereby opened.

At least the portion facing the aperture for the head part 13 of theslide guide 18 carrying the shutter unit 215 provided to the uppercartridge half 3 is of a height H₁ not protruding from the lower surface2 a of the optical disc 2 facing the lower cartridge half 4, as shown inFIG. 24, when the optical disc 2 in the disc cartridge 201, loaded inposition in the height-wise direction on the cartridge loading section67 has been loaded in position on the turntable 66.

The disc cartridge 201, constructed as described above, is able not onlyto locate an entire optical pickup 68, as a head part for reading outinformation signals, recorded on the optical disc, within the maincartridge body unit 5, as shown in FIG. 29, when the shutter unit 215has been moved to open the aperture for the head part 13, but also tolocate the components of the optical block 72, other than an objectivelens 71, condensing the light beam, scanning the signal recording areaof the optical disc 2, outwardly of the main cartridge body unit 5, asthe objective lens 71 is located within the main cartridge body unit 5,as shown in FIG. 20, when the optical pickup 68 has been moved to aposition scanning the outer rim of the optical disc 2.

As a result, with the disc cartridge 201, according to the presentinvention, the optical pickup 68 may be located at an optional positionacross the inner and outer rims of the main cartridge body unit 5, asthe optical pickup is kept in proximity to the optical disc 2, and hencethe signal recording area may be provided up to the outer rim of theoptical disc 2, thus increasing the recording capacity of the opticaldisc 2. Moreover, since the optical pickup 68 may be located inproximity to the optical disc 2, the numerical aperture NA of theobjective lens 71 may be increased, and hence the beam spot of the lightbeam condensed on the signal recording area of the optical disc 2 may bereduced, thereby improving the recording density of the informationsignals recorded on the optical disc 2. In addition, since the recordingdensity may be improved with increase in the recording capacity, theoptical disc 2 of a preset recording capacity may be reduced in size.The optical disc 2 may be scanned as the optical pickup 68 is located atan optional position across the inner and outer rims of the maincartridge body unit 5, the main cartridge body unit 5 and hence therecording and/or reproducing apparatus employing the disc cartridge 201may be reduced in size.

The disc cartridge 201, described above, includes the shutter unit 215for closing the aperture for the head part 13. However, the disccartridge according to the present invention may also be devoid of theshutter member, with the aperture for the head part being then opened.With this disc cartridge, the portion of the upstanding peripheral wallsection of the lower cartridge half, lying opposite to the aperture forthe head part, is opened by being formed with the cut-out 25. That is,the portion of the aperture for the head part, extending from the innerrim up to the outer rim of the main cartridge body unit 5, is opened.The portion of the upstanding peripheral wall section, facing theentrance aperture for the head part, is also cut out.

When the present disc cartridge is loaded in position along theheight-wise direction on the cartridge loading section in the discrecording and/or reproducing apparatus, the portion of the uppercartridge half facing the aperture for the head part and the entranceaperture for the head part is of a height H₁ not protruding from thelower surface 2 a facing the lower cartridge half 4 of the optical disc2, as in the case of the disc cartridge 201.

With this disc cartridge, the optical pickup may be positioned acrossthe inner and outer sides of the main cartridge body unit, as theoptical pickup is close to the optical disc, so that the signalrecording area may be formed up to the outer rim of the optical disc,thereby increasing the recording capacity of the optical disc.

Although the disc cartridge having housed therein the replay-onlyoptical disc has been explained in the foregoing, the present inventionmay similarly be applied to a recording and/or reproducing optical discadapted for re-recording the information signals, or other types of therecording mediums, with comparable merits.

INDUSTRIAL UTILIZABILITY

Since the disc cartridge according to the present invention may bereduced in size, it may be used with advantage as a recording medium fora recording and/or reproducing apparatus reduced in size for portableuse.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

1. A disc cartridge comprising: a disc; a main cartridge body unithaving said disc rotatably housed therein and including a recordingand/or reproducing aperture for exposing a portion of said disc tooutside across inner and outer rims of said disc, the recording and/orreproducing aperture defining a first side and a second side of the maincartridge body unit; and an entrance part for a head unit of a recordingand/or reproducing apparatus, said entrance part being a recess which isformed in the first side of the main cartridge body unit and extendingto said recording and/or reproducing aperture, for entrance of at leasta portion of said head unit below an outer surface of the main cartridgebody unit; wherein the portion of said recording and/or reproducingaperture along the outer rim of said main cartridge body unit is openedby being formed with a cut-out formed in a wall of the main cartridgebody unit and extending in a direction along the thickness of said disc,and a depth of said entrance part is less than a thickness of a wall ofthe first side of said main cartridge body unit so as to not exposeanother portion of the disc located adjacent to the recess to theoutside.
 2. The disc cartridge according to claim 1 wherein said cut-outis formed to a height at least equal to a thickness of a surface of themain cartridge body unit.
 3. The disc cartridge according to claim 1wherein said cut-out is formed so that, when a recording and/orreproducing means of a recording and/or reproducing apparatus isintroduced into said recording and/or reproducing aperture for recordingand/or reproduction in the vicinity of the outer rim of said disc, partof said recording and/or reproducing means is located outside of saidmain cartridge body unit.
 4. The disc cartridge according to claim 1wherein the inserting lateral side of said main cartridge body unit intoa recording and/or reproducing apparatus is a substantially semicirculararcuate section, having a center corresponding to a center of the dischoused in said main cartridge body unit, and wherein said recordingand/or reproducing aperture is formed facing to a lateral side of saidmain cartridge body unit other than said inserting lateral side arcuatein profile.
 5. The disc cartridge according to claim 4, wherein alateral side of said main cartridge body unit opposing said insertinglateral side of said main cartridge body unit is a substantiallysemicircular arcuate section, having a radius larger than a radius ofthe substantially semicircular arcuate section of the inserting lateralside of said main cartridge body unit, wherein the lateral side of saidmain cartridge body unit into which said recording and/or reproducingapparatus is formed is a substantially linear section.